As we mark one year this week since Border Patrol Agent Brian Terry was shot to death in Arizona -- with guns allowed to drift over the Mexican line found at the scene -- we certainly know much more about Operation Fast and Furious.

That's the bad-idea-executed-poorly child of the Bureau of Alcohol, Tobacco, Firearms and Explosives, sanctioned by your own U.S. Justice Department. In addition to Terry's death, another federal agent may have been killed in Mexico by a walked gun, and the case could well have ties to North Texas.

What we still don't know -- what Attorney General Eric Holder with great determination will not say -- is who in Washington signed off on this awful idea of letting straw purchasers cart off armloads of high-powered weapons, headed to Mexico. The stated plan was to track them to the cartels, which worked out about as well as one might expect. Hundreds of guns disappeared and now are turning up at crime scenes on both sides of the border.

Holder last week had another bob-and-weave session with a congressional committee, managing to reveal as little as possible. However, he did let us know that while Justice did dump hundreds of emails in response to a subpoena, none were addressed to him or had been sent by him. And that he has a personal email account, along with his government account. And that lying isn't the same as not telling the truth, depending on one's "state of mind."

Several dozen Republicans in Congress have called for his resignation. Others have demanded he hold Justice subordinates accountable. (And, no, shifting a few folks into no-work, no-speak jobs isn't accountability.) Meanwhile, a Border Patrol agent is dead and his family still has no clarity on who is responsible.

At some point, one might think, Holder becomes more of a liability to the Obama re-election campaign than a 50-50 incumbent can stand. At the very least, I can't imagine congressional Republicans letting this drop, and the longer Holder stonewalls, the longer his name -- and connection to his boss -- stays in the news.